While around 3% NB4, 6% EL-4 and 13% BW5147 cells remained alive (Annexin V- and PI-) at a concentration of 4 μM As2O3, remarkably, the percentages of living cells were around 65% for Jurkat cells, and between 80% and 90% for HPB-ALL and L1210 cells (Figure 1A). This evidence concerns the gene ANXA5 and acute lymphoblastic leukemia.